1. Field of the Invention
The present invention relates to a cover tape for packaging semiconductor device which ensures quality and reliability of a semiconductor device by protecting the outer shape of the semiconductor device, and is capable of improving the mounting speed of the semiconductor device by shipment in tape, and a package for semiconductor device using the cover tape for packaging semiconductor device.
2. Description of the Related Art
The shipment in embossed tape has been employed as a delivering embodiment of a semiconductor device for mounting the semiconductor device on a substrate. In the shipment in embossed tape, the semiconductor device is delivered packaged in a package which contains an embossed tape on which pockets for containing the semiconductor device are formed in accordance with the shape of the semiconductor device such as LSIs, etc. and a cover tape which packs the embossed tape. The semiconductor device contained in the package is taken out after the cover tape is peeled off and mounted on a surface of the substrate automatically. Because the embossed tape is advantageous in being able to transport the semiconductor device such as LSIs, etc. in large quantity and in enabling high-speed mounting of the semiconductor device on a substrate by users, the demand for shipment in embossed tape is growing in recent years.
However, with a progress of polarization (grow in size and downsizing) of semiconductor devices, small, thin and light electronic components such as CSP/CHIP, etc. are being shipped or mounted in tray because shipment in embossed tape is difficult due to manufacturing of the embossed tape which makes the high-precision processing impossible.
The shipment in tray has a problem in mounting speed which is two to three times slower compared to that of the shipment in tape because of the delay caused by the use of intermediate table when a general-purpose mounting device is used. Moreover, there are two types of mounting device: general-purpose type which is applicable for both shipments in tray and tape and high-speed type which is applicable only for shipment in tape. The mounting device of high-speed type has a problem that it is not applicable for shipment in tray.
Therefore, it is necessary to improve the embossed tape and to realize the use of the high-speed mounting device by shipment in embossed tape in order to realize high-speed mounting of the semiconductor device.
For example, a tape wound on a reel as shown in FIG. 1A is known as the embossed tape. An enlarged view of the embossed tape in X portion surrounded by dashed line in FIG. 1A is shown in FIG. 1B and a cross-sectional view is shown in FIG. 1C. As shown in FIG. 1C, semiconductor devices, IC chips 110 are packed in a package containing an embossed tape 100 on which pockets 100A which contain the IC chips 110 are formed and a cover tape 120 which packs the embossed tape 100. The IC chips 110 contained in the pockets 100A are transported in high speed, and taken out after the cover tape 120 is peeled off in high speed during mounting on the substrate. During this time, there has been a problem with conventional cover tape 120 that the IC chips 110 pop out from the pockets 100A due to absorption at low-pressure and static electricity, etc.
For this reason, cover tapes on which openings 125 or openings 126 are formed as shown in FIGS. 1E and 1G (Japanese Patent Application Laid-Open (JP-A) No. 4-031215 and 2005-132421) and a cover tape on which projections 127 are formed as shown in FIG. 1I (JP-A No. 2005-35636) have been proposed. These cover tapes 120 inhibit popping out, etc. of the semiconductor devices (IC chips 110) which occurs during peeling off of the cover tapes 120 by decreasing the contact area between upper surface of the semiconductor devices (IC chips 110) and the cover tapes 120 with the openings 125, the openings 126 or the projections 127. However, when forming the projections 127, exclusive cover tape is needed for every pockets 100A pitch. Furthermore, it becomes necessary to make the depth of the pockets 100A as much deeper as the height “t” of the projections on the cover tape 120 on which the projections 127 are formed as shown in FIG. 1I and the cover tape 120 on which the openings 126 are formed in form of projection as shown in FIG. 1G. Further, when the openings 125 shown in FIG. 1E and the openings 126 shown in FIG. 1G are formed, an insulating layer 122 is in contact with or adjacent to the semiconductor device because end faces of the openings 125 and 126 of the cover tapes 120 are exposed as shown in cross-sectional views in FIGS. 1F and 1H. Generally, a sheet S prior to forming of cover tape 120 has a two-layer structure containing an insulating layer 121 and an antistatic layer 122 for material cost reduction as shown in FIG. 1D. Because the insulating layer 121, which takes over the most part of the sheet S, does not have conductive and antistatic functions, a problem of circuit destruction due to charged semiconductor device or dust generated from the end faces of the openings 125 and 126 which attaches to the semiconductor device during mounting on the substrate occurs as shown in FIGS. 1F and 1H.
In consequence, a cover tape for packaging semiconductor device which prevents generation of powder dust by inhibiting static electricity, ensures quality and reliability of a semiconductor device and is capable of improving the mounting speed of the semiconductor device by shipment in tape have not yet been provided and further development is desired.
It is an object of the present invention to solve foregoing problems and to fulfill the following purposes.
The purpose of the present invention is to provide a cover tape for packaging semiconductor device which ensures quality and reliability of a semiconductor device by protecting the outer shape of the semiconductor device, and is capable of improving the mounting speed of the semiconductor device by shipment in tape, and a package for semiconductor device using the cover tape for packaging semiconductor device.